Automatic closing device for fire-doors.



of the borough of UNITED STATES PATENT L FREDERICK'W. MARTIN, OF NEW YORK, N. Y., ASSIGNOR TO FRANKLIN RAILWAY SUPPLY COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE,

Specification of Letters Patent.

Patented Mar. 5, 1918.

Application led February 2, 1916. Serial No. 75,784.

To all whom tmay concern.'

Be it known that I FREDERICK W. MARTIN, Manhattan, in the city, county, and State of New York, have invented a certain new and useful Improve- -ment in Automatic Closing Devices for Fire- Doors, of which improvement the following is a specification.

This invention relates to fluid pressure motors for operating certain closures or other devices, and is particularly adapted for use in the opening and closing of fire doors of boiler furnaces, the object being to provide improved means for automatically efecting a positive closing of the fire door within a, predetermined interval after the same has been opened, and thereby prevent the fireman from holding the door open for a longer period.

In this re door apparatus as usedon locomotives, the iiuid pressure motor for actuating the doors is usually controlled by a valve operated by a pedal device, and it has been the practice of some firemen to hold the foot upon the pedal with the door open a suiiiciently long period of time to deliver several shovelfuls of fuel into the furnace. This practice is ob'ectionable, as large drafts of cold air are a itted to the furnace at such times through the wide open door, which tends to cool the re and chill the water heating surfaces. With my improvement this is positively prevented, as the door will be promptly closed after a predetermined time even though the fireman retains his foot on the pedal.

My present improvement relates more particularly to that type of door operating and closing devices, including a fluid pressure motor, an expansion chamber of a 'ven capacityor volume and having a restricted inlet port to serve as a timing element in which the pressure increases at a certain rate, and valve means operated by a certain pressure in said chamber to cut oil the supply of fluid to the motor, whereupon the door may close automatically eitherby gravity or otherwise. One of the features of my improvement comprises a door motor having a' normally open port or passage from the manually operated peda valve into the cylinder, and an auxiliary valve operated by the pressure in the -expansion chamber for closing said port or passage at opening of the pedal valve. Another feature comprises means for automatically re' turning the auxiliary valve to its normal position with said port or passage open, when the pedal valve is released. These and other objects will now more fully appear from the following detailed description, the features of novelty being set forth in the claims.

In the accompanying drawing, the figure shows, in vertical section, one form of motor and expansion chamber device embodying my improvement, and connected to a pair of fire doors.

My improvement may be applied to various forms of iiuid pressure motors and re doors, but in the drawing I have illustrated the same in connection with a fluid pressure motor comprising a horizontal cylinder, 10, containing a piston, 9, having a pin and link connection with one of the doors, 6, which doors are provided with intermeshing segmental gears, 8, and pivoted to swing laterally and vertically. The doors are opened by admittin Huid under pressure to the working face o the piston, and are normally closed by gravity when said fluid is exhausted to the atmosphere. For this operation a manual valve, such as 13, is provided for controlling the admission of duid, such as compressed air, from a source of supply, 11, to the inlet port, 15, said valve also controlling the exhaust port, 16.

011 locomotive boilers the manual valve is usually operated by a pedal device having an arm, 23, for raising the valve to its open 'position.v According tothe usual and proper practicethe fireman steps upon the pedal to raise the valve, and thereby close the exhaust port, and open the admission to supply uid to the piston to o en the doors at the time he delivers a shove ful 'of coal. He then releases the pedal to close the valve, and open the exhaust port, whereupon the fluid in the cylinder esca es to the atmosphere, and the doors immediately close by gravity. At the time of delivery of the next shovelful,

the valve is adgain raised, and the operation is re eate Y v According to this improvement, the passages, 14 andI 15, from the manually operated valve, 13, to the cylinder, are normally open, which provides for the free admission of iiuid to, and the exhaust of the same from,

the cylinder in the normal operation of the pedal valve to open and close the furnace` door. An auxiliary valve device, preferably in the form of a differential piston valve, 32, is provided for closing the port or passage, 15, when the pressure in the ex pansion. chamber reaches a predetermined amount. In the construction, as shown, theA diiferential piston valve is made hollow and. mounted in a chamber formed in the cylinderf head, and the expansion chamber, 31, com-3 prises the space within the hollow pistonv valve and the chamber formed in the cap, 30, of the valve chamber. This gives the desired capacity or volume to the expansion chamber which is provided with the restrict-d ed inlet port, 33, formed through the smallerhead of the hollow differential piston valve,\ the larger end being subject to the pressure l in the expansion chamber. The piston, 32, is'provided with a groove, 34, adapted to register with exhaust ports, 35, and 35a, and open a separate exhaust from the cylinder when actuated by the pressure in the expan-l sion chamber to cut 0E the admission port, 15. A movable plunger, 36, subject at all times to fluid pressure from the source of supply, 11, is mountedrin the upper end of the valve chamber and bears upon the smaller end of the diilerential piston valve to return the same to its normal position and open the admission port, 15, when the pedal valve is released and the fluid from the expansion chamber escapes to the atmosphe're through ports and passages, 33, 14 and 16.

When the valve, 13, is raised by the pedal device, the exhaust port, 16, is closed by the stem of valve, 13, and fluid is admitted through passage, 14, to the valve chamber, where it acts u on the upper or smaller end of the diiierent1al piston valve, and through port, 15, into the c linder, 10, moving the piston, 9, to open t e dnors. At the same time fluid feeds through the restricted port, 33, into the expansion chamber, 31. If the pedal device be then promptly released, the valve, 13, closes and o ens exhaust port, 16, whereupon the uid rom the cylinder and from the expansion chamber escapes to the i atmosphere, and the doors close by gravity.

If, however, the pedal device is retained in its olpen position, with the valve, 13, raised, t e pressure continues to increase in the expansion chamber, 31, and, acting on the llarger area of the dili'erential piston valve, 32, overcomes the opposing pressure on the smallerarea and moves the iston valve upward to close the port, 15, an open the separate exhaust ort, 35, at a predetermined interval of t1me after the opening of the ledal valve. The iuid then escapes from t'e cylinder, and the doors are promptly closed. The differential piston valve, 32, and plunger, 36, will remain 1n the 1,aee,ose

upper position, being held bythe pressure in the expansion chamber, until the pedal device is released, and valve, 13, closed, whereupon the pressure will be released from the expansion chamber, and the differential piston valve will be automatically returned to its normal position with port, 15, open, by the movement of the plunger, 36, whichis subject to the Huid pressure from the supply pipe, 11.

lt is, therefore, apparent that, with my improvement, the lire doors will be automatically closed within a predetermined short interval of time after the opening of the manual valve even though the fireman retains his pedal device open, thereb insuring what is termed single shovel firing, or the delivery of but one shovelful of fuel into the furnace at each opening ,Of the door.

Having now described my invention, what l claim as new and desire to secure by Letters Patent is: l

1. In a lire door apparatus, the combination of a door, a cylinder and piston for operating the door, said cylinder havin a normally open admission ort, a manualy operated valve for controlling the supply of fluid through said port, an expansion chamber, and a valve operated by the pressure in said chamber for automatically closing said port at a predetermined time after the opening of said manual valve.

2. l'n a lire door apparatus, the combina tion of a door, a cylinder and iston for op- 100 erating the doorsaid cylinder aving anormally open admission port and a separate exhaust port, a manually o erated valve for controlling the Isupply of uid through said admission port, and the exhaust therefrom, 105 an expansion chamber having a restricted inlet port, and a valve operated by the ressure 1n said chamber for closing the a isl sion port and opening the separate exhaust port from the cylinder at a predetermined 110 time after the openin of the manual valve, thus permitting the c sing of the door.

3. In a lire door ap aratus, the combina. tion of a door, a cylinder and piston for operating the door, said cylinder having a nor- 115 mally open admission port, a manuall operated valve for controlling the supp y of iuid through said port, an expansion chamber having a restricted inlet port, and a dif'- ferential piston-valve for controlling said .12u admission port and subject on one "s1de to the pressure in the expansion chamber and on the other side to pressure of fluid admitted through said manual valve.

4. In a fire door ap aratus, the combina- 125 tion of a door, a cylin er and piston for operating the door, said cylinder having a nor mally open admission port, a manuall operated valve for controlling the supp y of fluid through said port, an expansion cham- 130 ber, a valve operated by the pressure in said chamber for automatically closing said port at a predetermined time after the opening of said manual valve, and means for automatically returning said valve to open the admission port When the manual valve is released.

5. In a fire door apparatus, the combination of a door, a cylinder and piston for operating the door, said cylinder having a normally open admission port, a manually operated valve for controlling the supply of fluid through said port, an expansion chamber, a valve operated by the pressure in said chamber for automatically closing said port at a predetermined time after the opening of said manual valve, and a fluid pressure actuated plunger for returning said valve to open said admission port when the manual valve is released.

6. In a fire door apparatus, the combination of a door, a cylinder and piston for operating the door, said cylinder having a normally open admission port, a manually operated Valve for controlling the supply of iuid through said port; an expansion cham.- ber having a restricted inlet port, a hollow dierential piston valve forming a portion of the expansion chamber and operated by the pressure in said chamber to close said' admission port at a predetermined time after the opening of the manual valve.

FREDERICK W. MARTIN. Witnesses:

C. DOWNY, C. N. BUCK. 

